linux-imx

/*

 * Copyright (c) 2006-2009 Simtec Electronics

 *  http://armlinux.simtec.co.uk/

 *  Ben Dooks <ben@simtec.co.uk>

 *  Vincent Sanders <vince@simtec.co.uk>

 *

 * S3C2440/S3C2442 CPU Frequency scaling

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

*/

​

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#include <linux/init.h>

#include <linux/module.h>

#include <linux/interrupt.h>

#include <linux/ioport.h>

#include <linux/cpufreq.h>

#include <linux/device.h>

#include <linux/delay.h>

#include <linux/clk.h>

#include <linux/err.h>

#include <linux/io.h>

​

#include <asm/mach/arch.h>

#include <asm/mach/map.h>

​

#include <mach/regs-clock.h>

​

#include <plat/cpu.h>

#include <plat/cpu-freq-core.h>

​

static struct clk *xtal;

static struct clk *fclk;

static struct clk *hclk;

static struct clk *armclk;

​

/* HDIV: 1, 2, 3, 4, 6, 8 */

​

static inline int within_khz(unsigned long a, unsigned long b)

{

    long diff = a - b;

​

    return (diff >= -1000 && diff <= 1000);

}

​

/**

 * s3c2440_cpufreq_calcdivs - calculate divider settings

 * @cfg: The cpu frequency settings.

 *

 * Calcualte the divider values for the given frequency settings

 * specified in @cfg. The values are stored in @cfg for later use

 * by the relevant set routine if the request settings can be reached.

 */

static int s3c2440_cpufreq_calcdivs(struct s3c_cpufreq_config *cfg)

{

    unsigned int hdiv, pdiv;

    unsigned long hclk, fclk, armclk;

    unsigned long hclk_max;

​

    fclk = cfg->freq.fclk;